Explain the difference between open and closed gas turbine cycles.

Open and closed gas turbine cycles are fundamentally different in how they manage exhaust and working gases within the system. In an open cycle, the working fluid—typically air—is drawn into the gas turbine, compressed, and heated before it expands through the turbine to do work. After passing through the turbine, the hot exhaust gases are expelled into the atmosphere, providing no opportunity for those gases to be reused within the cycle.

In contrast, a closed cycle utilizes a working fluid, often a gas that circulates continuously within the system, without being discharged into the atmosphere. In this cycle, the gas is compressed, heated, and then expanded through the turbine, but it is then recirculated back into the compressor. This allows the system to maintain efficiency and minimize wasted energy since the same working fluid is being reused.

The option indicating that open cycles allow exhaust gases to exit while closed cycles recirculate gases accurately captures the critical operational distinction between the two types of cycles. This understanding is essential for recognizing how gas turbine systems manage energy and operational efficiency.